xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision f9a82c48)
1 /* AF_RXRPC sendmsg() implementation.
2  *
3  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public Licence
8  * as published by the Free Software Foundation; either version
9  * 2 of the Licence, or (at your option) any later version.
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/net.h>
15 #include <linux/gfp.h>
16 #include <linux/skbuff.h>
17 #include <linux/export.h>
18 #include <linux/sched/signal.h>
19 
20 #include <net/sock.h>
21 #include <net/af_rxrpc.h>
22 #include "ar-internal.h"
23 
24 /*
25  * Wait for space to appear in the Tx queue or a signal to occur.
26  */
27 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
28 					 struct rxrpc_call *call,
29 					 long *timeo)
30 {
31 	for (;;) {
32 		set_current_state(TASK_INTERRUPTIBLE);
33 		if (call->tx_top - call->tx_hard_ack <
34 		    min_t(unsigned int, call->tx_winsize,
35 			  call->cong_cwnd + call->cong_extra))
36 			return 0;
37 
38 		if (call->state >= RXRPC_CALL_COMPLETE)
39 			return call->error;
40 
41 		if (signal_pending(current))
42 			return sock_intr_errno(*timeo);
43 
44 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
45 		mutex_unlock(&call->user_mutex);
46 		*timeo = schedule_timeout(*timeo);
47 		if (mutex_lock_interruptible(&call->user_mutex) < 0)
48 			return sock_intr_errno(*timeo);
49 	}
50 }
51 
52 /*
53  * Wait for space to appear in the Tx queue uninterruptibly, but with
54  * a timeout of 2*RTT if no progress was made and a signal occurred.
55  */
56 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
57 					    struct rxrpc_call *call)
58 {
59 	rxrpc_seq_t tx_start, tx_win;
60 	signed long rtt2, timeout;
61 	u64 rtt;
62 
63 	rtt = READ_ONCE(call->peer->rtt);
64 	rtt2 = nsecs_to_jiffies64(rtt) * 2;
65 	if (rtt2 < 1)
66 		rtt2 = 1;
67 
68 	timeout = rtt2;
69 	tx_start = READ_ONCE(call->tx_hard_ack);
70 
71 	for (;;) {
72 		set_current_state(TASK_UNINTERRUPTIBLE);
73 
74 		tx_win = READ_ONCE(call->tx_hard_ack);
75 		if (call->tx_top - tx_win <
76 		    min_t(unsigned int, call->tx_winsize,
77 			  call->cong_cwnd + call->cong_extra))
78 			return 0;
79 
80 		if (call->state >= RXRPC_CALL_COMPLETE)
81 			return call->error;
82 
83 		if (timeout == 0 &&
84 		    tx_win == tx_start && signal_pending(current))
85 			return -EINTR;
86 
87 		if (tx_win != tx_start) {
88 			timeout = rtt2;
89 			tx_start = tx_win;
90 		}
91 
92 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
93 		timeout = schedule_timeout(timeout);
94 	}
95 }
96 
97 /*
98  * wait for space to appear in the transmit/ACK window
99  * - caller holds the socket locked
100  */
101 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
102 				    struct rxrpc_call *call,
103 				    long *timeo,
104 				    bool waitall)
105 {
106 	DECLARE_WAITQUEUE(myself, current);
107 	int ret;
108 
109 	_enter(",{%u,%u,%u}",
110 	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
111 
112 	add_wait_queue(&call->waitq, &myself);
113 
114 	if (waitall)
115 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
116 	else
117 		ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
118 
119 	remove_wait_queue(&call->waitq, &myself);
120 	set_current_state(TASK_RUNNING);
121 	_leave(" = %d", ret);
122 	return ret;
123 }
124 
125 /*
126  * Schedule an instant Tx resend.
127  */
128 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
129 {
130 	spin_lock_bh(&call->lock);
131 
132 	if (call->state < RXRPC_CALL_COMPLETE) {
133 		call->rxtx_annotations[ix] =
134 			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
135 			RXRPC_TX_ANNO_RETRANS;
136 		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
137 			rxrpc_queue_call(call);
138 	}
139 
140 	spin_unlock_bh(&call->lock);
141 }
142 
143 /*
144  * Notify the owner of the call that the transmit phase is ended and the last
145  * packet has been queued.
146  */
147 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
148 				rxrpc_notify_end_tx_t notify_end_tx)
149 {
150 	if (notify_end_tx)
151 		notify_end_tx(&rx->sk, call, call->user_call_ID);
152 }
153 
154 /*
155  * Queue a DATA packet for transmission, set the resend timeout and send the
156  * packet immediately
157  */
158 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
159 			       struct sk_buff *skb, bool last,
160 			       rxrpc_notify_end_tx_t notify_end_tx)
161 {
162 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
163 	unsigned long now;
164 	rxrpc_seq_t seq = sp->hdr.seq;
165 	int ret, ix;
166 	u8 annotation = RXRPC_TX_ANNO_UNACK;
167 
168 	_net("queue skb %p [%d]", skb, seq);
169 
170 	ASSERTCMP(seq, ==, call->tx_top + 1);
171 
172 	if (last)
173 		annotation |= RXRPC_TX_ANNO_LAST;
174 
175 	/* We have to set the timestamp before queueing as the retransmit
176 	 * algorithm can see the packet as soon as we queue it.
177 	 */
178 	skb->tstamp = ktime_get_real();
179 
180 	ix = seq & RXRPC_RXTX_BUFF_MASK;
181 	rxrpc_get_skb(skb, rxrpc_skb_tx_got);
182 	call->rxtx_annotations[ix] = annotation;
183 	smp_wmb();
184 	call->rxtx_buffer[ix] = skb;
185 	call->tx_top = seq;
186 	if (last)
187 		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
188 	else
189 		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
190 
191 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
192 		_debug("________awaiting reply/ACK__________");
193 		write_lock_bh(&call->state_lock);
194 		switch (call->state) {
195 		case RXRPC_CALL_CLIENT_SEND_REQUEST:
196 			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
197 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
198 			break;
199 		case RXRPC_CALL_SERVER_ACK_REQUEST:
200 			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
201 			now = jiffies;
202 			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
203 			if (call->ackr_reason == RXRPC_ACK_DELAY)
204 				call->ackr_reason = 0;
205 			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
206 			if (!last)
207 				break;
208 			/* Fall through */
209 		case RXRPC_CALL_SERVER_SEND_REPLY:
210 			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
211 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
212 			break;
213 		default:
214 			break;
215 		}
216 		write_unlock_bh(&call->state_lock);
217 	}
218 
219 	if (seq == 1 && rxrpc_is_client_call(call))
220 		rxrpc_expose_client_call(call);
221 
222 	ret = rxrpc_send_data_packet(call, skb, false);
223 	if (ret < 0) {
224 		switch (ret) {
225 		case -ENETUNREACH:
226 		case -EHOSTUNREACH:
227 		case -ECONNREFUSED:
228 			rxrpc_set_call_completion(call,
229 						  RXRPC_CALL_LOCAL_ERROR,
230 						  0, ret);
231 			goto out;
232 		}
233 		_debug("need instant resend %d", ret);
234 		rxrpc_instant_resend(call, ix);
235 	} else {
236 		unsigned long now = jiffies, resend_at;
237 
238 		if (call->peer->rtt_usage > 1)
239 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
240 		else
241 			resend_at = rxrpc_resend_timeout;
242 		if (resend_at < 1)
243 			resend_at = 1;
244 
245 		resend_at += now;
246 		WRITE_ONCE(call->resend_at, resend_at);
247 		rxrpc_reduce_call_timer(call, resend_at, now,
248 					rxrpc_timer_set_for_send);
249 	}
250 
251 out:
252 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
253 	_leave("");
254 }
255 
256 /*
257  * send data through a socket
258  * - must be called in process context
259  * - The caller holds the call user access mutex, but not the socket lock.
260  */
261 static int rxrpc_send_data(struct rxrpc_sock *rx,
262 			   struct rxrpc_call *call,
263 			   struct msghdr *msg, size_t len,
264 			   rxrpc_notify_end_tx_t notify_end_tx)
265 {
266 	struct rxrpc_skb_priv *sp;
267 	struct sk_buff *skb;
268 	struct sock *sk = &rx->sk;
269 	long timeo;
270 	bool more;
271 	int ret, copied;
272 
273 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
274 
275 	/* this should be in poll */
276 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
277 
278 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
279 		return -EPIPE;
280 
281 	more = msg->msg_flags & MSG_MORE;
282 
283 	if (call->tx_total_len != -1) {
284 		if (len > call->tx_total_len)
285 			return -EMSGSIZE;
286 		if (!more && len != call->tx_total_len)
287 			return -EMSGSIZE;
288 	}
289 
290 	skb = call->tx_pending;
291 	call->tx_pending = NULL;
292 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
293 
294 	copied = 0;
295 	do {
296 		/* Check to see if there's a ping ACK to reply to. */
297 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
298 			rxrpc_send_ack_packet(call, false, NULL);
299 
300 		if (!skb) {
301 			size_t size, chunk, max, space;
302 
303 			_debug("alloc");
304 
305 			if (call->tx_top - call->tx_hard_ack >=
306 			    min_t(unsigned int, call->tx_winsize,
307 				  call->cong_cwnd + call->cong_extra)) {
308 				ret = -EAGAIN;
309 				if (msg->msg_flags & MSG_DONTWAIT)
310 					goto maybe_error;
311 				ret = rxrpc_wait_for_tx_window(rx, call,
312 							       &timeo,
313 							       msg->msg_flags & MSG_WAITALL);
314 				if (ret < 0)
315 					goto maybe_error;
316 			}
317 
318 			max = RXRPC_JUMBO_DATALEN;
319 			max -= call->conn->security_size;
320 			max &= ~(call->conn->size_align - 1UL);
321 
322 			chunk = max;
323 			if (chunk > msg_data_left(msg) && !more)
324 				chunk = msg_data_left(msg);
325 
326 			space = chunk + call->conn->size_align;
327 			space &= ~(call->conn->size_align - 1UL);
328 
329 			size = space + call->conn->security_size;
330 
331 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
332 
333 			/* create a buffer that we can retain until it's ACK'd */
334 			skb = sock_alloc_send_skb(
335 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
336 			if (!skb)
337 				goto maybe_error;
338 
339 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
340 
341 			_debug("ALLOC SEND %p", skb);
342 
343 			ASSERTCMP(skb->mark, ==, 0);
344 
345 			_debug("HS: %u", call->conn->security_size);
346 			skb_reserve(skb, call->conn->security_size);
347 			skb->len += call->conn->security_size;
348 
349 			sp = rxrpc_skb(skb);
350 			sp->remain = chunk;
351 			if (sp->remain > skb_tailroom(skb))
352 				sp->remain = skb_tailroom(skb);
353 
354 			_net("skb: hr %d, tr %d, hl %d, rm %d",
355 			       skb_headroom(skb),
356 			       skb_tailroom(skb),
357 			       skb_headlen(skb),
358 			       sp->remain);
359 
360 			skb->ip_summed = CHECKSUM_UNNECESSARY;
361 		}
362 
363 		_debug("append");
364 		sp = rxrpc_skb(skb);
365 
366 		/* append next segment of data to the current buffer */
367 		if (msg_data_left(msg) > 0) {
368 			int copy = skb_tailroom(skb);
369 			ASSERTCMP(copy, >, 0);
370 			if (copy > msg_data_left(msg))
371 				copy = msg_data_left(msg);
372 			if (copy > sp->remain)
373 				copy = sp->remain;
374 
375 			_debug("add");
376 			ret = skb_add_data(skb, &msg->msg_iter, copy);
377 			_debug("added");
378 			if (ret < 0)
379 				goto efault;
380 			sp->remain -= copy;
381 			skb->mark += copy;
382 			copied += copy;
383 			if (call->tx_total_len != -1)
384 				call->tx_total_len -= copy;
385 		}
386 
387 		/* check for the far side aborting the call or a network error
388 		 * occurring */
389 		if (call->state == RXRPC_CALL_COMPLETE)
390 			goto call_terminated;
391 
392 		/* add the packet to the send queue if it's now full */
393 		if (sp->remain <= 0 ||
394 		    (msg_data_left(msg) == 0 && !more)) {
395 			struct rxrpc_connection *conn = call->conn;
396 			uint32_t seq;
397 			size_t pad;
398 
399 			/* pad out if we're using security */
400 			if (conn->security_ix) {
401 				pad = conn->security_size + skb->mark;
402 				pad = conn->size_align - pad;
403 				pad &= conn->size_align - 1;
404 				_debug("pad %zu", pad);
405 				if (pad)
406 					skb_put_zero(skb, pad);
407 			}
408 
409 			seq = call->tx_top + 1;
410 
411 			sp->hdr.seq	= seq;
412 			sp->hdr._rsvd	= 0;
413 			sp->hdr.flags	= conn->out_clientflag;
414 
415 			if (msg_data_left(msg) == 0 && !more)
416 				sp->hdr.flags |= RXRPC_LAST_PACKET;
417 			else if (call->tx_top - call->tx_hard_ack <
418 				 call->tx_winsize)
419 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
420 
421 			ret = conn->security->secure_packet(
422 				call, skb, skb->mark, skb->head);
423 			if (ret < 0)
424 				goto out;
425 
426 			rxrpc_queue_packet(rx, call, skb,
427 					   !msg_data_left(msg) && !more,
428 					   notify_end_tx);
429 			skb = NULL;
430 		}
431 	} while (msg_data_left(msg) > 0);
432 
433 success:
434 	ret = copied;
435 out:
436 	call->tx_pending = skb;
437 	_leave(" = %d", ret);
438 	return ret;
439 
440 call_terminated:
441 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
442 	_leave(" = %d", call->error);
443 	return call->error;
444 
445 maybe_error:
446 	if (copied)
447 		goto success;
448 	goto out;
449 
450 efault:
451 	ret = -EFAULT;
452 	goto out;
453 }
454 
455 /*
456  * extract control messages from the sendmsg() control buffer
457  */
458 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
459 {
460 	struct cmsghdr *cmsg;
461 	bool got_user_ID = false;
462 	int len;
463 
464 	if (msg->msg_controllen == 0)
465 		return -EINVAL;
466 
467 	for_each_cmsghdr(cmsg, msg) {
468 		if (!CMSG_OK(msg, cmsg))
469 			return -EINVAL;
470 
471 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
472 		_debug("CMSG %d, %d, %d",
473 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
474 
475 		if (cmsg->cmsg_level != SOL_RXRPC)
476 			continue;
477 
478 		switch (cmsg->cmsg_type) {
479 		case RXRPC_USER_CALL_ID:
480 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
481 				if (len != sizeof(u32))
482 					return -EINVAL;
483 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
484 			} else {
485 				if (len != sizeof(unsigned long))
486 					return -EINVAL;
487 				p->call.user_call_ID = *(unsigned long *)
488 					CMSG_DATA(cmsg);
489 			}
490 			got_user_ID = true;
491 			break;
492 
493 		case RXRPC_ABORT:
494 			if (p->command != RXRPC_CMD_SEND_DATA)
495 				return -EINVAL;
496 			p->command = RXRPC_CMD_SEND_ABORT;
497 			if (len != sizeof(p->abort_code))
498 				return -EINVAL;
499 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
500 			if (p->abort_code == 0)
501 				return -EINVAL;
502 			break;
503 
504 		case RXRPC_ACCEPT:
505 			if (p->command != RXRPC_CMD_SEND_DATA)
506 				return -EINVAL;
507 			p->command = RXRPC_CMD_ACCEPT;
508 			if (len != 0)
509 				return -EINVAL;
510 			break;
511 
512 		case RXRPC_EXCLUSIVE_CALL:
513 			p->exclusive = true;
514 			if (len != 0)
515 				return -EINVAL;
516 			break;
517 
518 		case RXRPC_UPGRADE_SERVICE:
519 			p->upgrade = true;
520 			if (len != 0)
521 				return -EINVAL;
522 			break;
523 
524 		case RXRPC_TX_LENGTH:
525 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
526 				return -EINVAL;
527 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
528 			if (p->call.tx_total_len < 0)
529 				return -EINVAL;
530 			break;
531 
532 		case RXRPC_SET_CALL_TIMEOUT:
533 			if (len & 3 || len < 4 || len > 12)
534 				return -EINVAL;
535 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
536 			p->call.nr_timeouts = len / 4;
537 			if (p->call.timeouts.hard > INT_MAX / HZ)
538 				return -ERANGE;
539 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
540 				return -ERANGE;
541 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
542 				return -ERANGE;
543 			break;
544 
545 		default:
546 			return -EINVAL;
547 		}
548 	}
549 
550 	if (!got_user_ID)
551 		return -EINVAL;
552 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
553 		return -EINVAL;
554 	_leave(" = 0");
555 	return 0;
556 }
557 
558 /*
559  * Create a new client call for sendmsg().
560  * - Called with the socket lock held, which it must release.
561  * - If it returns a call, the call's lock will need releasing by the caller.
562  */
563 static struct rxrpc_call *
564 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
565 				  struct rxrpc_send_params *p)
566 	__releases(&rx->sk.sk_lock.slock)
567 	__acquires(&call->user_mutex)
568 {
569 	struct rxrpc_conn_parameters cp;
570 	struct rxrpc_call *call;
571 	struct key *key;
572 
573 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
574 
575 	_enter("");
576 
577 	if (!msg->msg_name) {
578 		release_sock(&rx->sk);
579 		return ERR_PTR(-EDESTADDRREQ);
580 	}
581 
582 	key = rx->key;
583 	if (key && !rx->key->payload.data[0])
584 		key = NULL;
585 
586 	memset(&cp, 0, sizeof(cp));
587 	cp.local		= rx->local;
588 	cp.key			= rx->key;
589 	cp.security_level	= rx->min_sec_level;
590 	cp.exclusive		= rx->exclusive | p->exclusive;
591 	cp.upgrade		= p->upgrade;
592 	cp.service_id		= srx->srx_service;
593 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
594 				     atomic_inc_return(&rxrpc_debug_id));
595 	/* The socket is now unlocked */
596 
597 	rxrpc_put_peer(cp.peer);
598 	_leave(" = %p\n", call);
599 	return call;
600 }
601 
602 /*
603  * send a message forming part of a client call through an RxRPC socket
604  * - caller holds the socket locked
605  * - the socket may be either a client socket or a server socket
606  */
607 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
608 	__releases(&rx->sk.sk_lock.slock)
609 	__releases(&call->user_mutex)
610 {
611 	enum rxrpc_call_state state;
612 	struct rxrpc_call *call;
613 	unsigned long now, j;
614 	int ret;
615 
616 	struct rxrpc_send_params p = {
617 		.call.tx_total_len	= -1,
618 		.call.user_call_ID	= 0,
619 		.call.nr_timeouts	= 0,
620 		.abort_code		= 0,
621 		.command		= RXRPC_CMD_SEND_DATA,
622 		.exclusive		= false,
623 		.upgrade		= false,
624 	};
625 
626 	_enter("");
627 
628 	ret = rxrpc_sendmsg_cmsg(msg, &p);
629 	if (ret < 0)
630 		goto error_release_sock;
631 
632 	if (p.command == RXRPC_CMD_ACCEPT) {
633 		ret = -EINVAL;
634 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
635 			goto error_release_sock;
636 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
637 		/* The socket is now unlocked. */
638 		if (IS_ERR(call))
639 			return PTR_ERR(call);
640 		ret = 0;
641 		goto out_put_unlock;
642 	}
643 
644 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
645 	if (!call) {
646 		ret = -EBADSLT;
647 		if (p.command != RXRPC_CMD_SEND_DATA)
648 			goto error_release_sock;
649 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
650 		/* The socket is now unlocked... */
651 		if (IS_ERR(call))
652 			return PTR_ERR(call);
653 		/* ... and we have the call lock. */
654 	} else {
655 		switch (READ_ONCE(call->state)) {
656 		case RXRPC_CALL_UNINITIALISED:
657 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
658 		case RXRPC_CALL_SERVER_PREALLOC:
659 		case RXRPC_CALL_SERVER_SECURING:
660 		case RXRPC_CALL_SERVER_ACCEPTING:
661 			ret = -EBUSY;
662 			goto error_release_sock;
663 		default:
664 			break;
665 		}
666 
667 		ret = mutex_lock_interruptible(&call->user_mutex);
668 		release_sock(&rx->sk);
669 		if (ret < 0) {
670 			ret = -ERESTARTSYS;
671 			goto error_put;
672 		}
673 
674 		if (p.call.tx_total_len != -1) {
675 			ret = -EINVAL;
676 			if (call->tx_total_len != -1 ||
677 			    call->tx_pending ||
678 			    call->tx_top != 0)
679 				goto error_put;
680 			call->tx_total_len = p.call.tx_total_len;
681 		}
682 	}
683 
684 	switch (p.call.nr_timeouts) {
685 	case 3:
686 		j = msecs_to_jiffies(p.call.timeouts.normal);
687 		if (p.call.timeouts.normal > 0 && j == 0)
688 			j = 1;
689 		WRITE_ONCE(call->next_rx_timo, j);
690 		/* Fall through */
691 	case 2:
692 		j = msecs_to_jiffies(p.call.timeouts.idle);
693 		if (p.call.timeouts.idle > 0 && j == 0)
694 			j = 1;
695 		WRITE_ONCE(call->next_req_timo, j);
696 		/* Fall through */
697 	case 1:
698 		if (p.call.timeouts.hard > 0) {
699 			j = msecs_to_jiffies(p.call.timeouts.hard);
700 			now = jiffies;
701 			j += now;
702 			WRITE_ONCE(call->expect_term_by, j);
703 			rxrpc_reduce_call_timer(call, j, now,
704 						rxrpc_timer_set_for_hard);
705 		}
706 		break;
707 	}
708 
709 	state = READ_ONCE(call->state);
710 	_debug("CALL %d USR %lx ST %d on CONN %p",
711 	       call->debug_id, call->user_call_ID, state, call->conn);
712 
713 	if (state >= RXRPC_CALL_COMPLETE) {
714 		/* it's too late for this call */
715 		ret = -ESHUTDOWN;
716 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
717 		ret = 0;
718 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
719 			ret = rxrpc_send_abort_packet(call);
720 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
721 		ret = -EINVAL;
722 	} else if (rxrpc_is_client_call(call) &&
723 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
724 		/* request phase complete for this client call */
725 		ret = -EPROTO;
726 	} else if (rxrpc_is_service_call(call) &&
727 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
728 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
729 		/* Reply phase not begun or not complete for service call. */
730 		ret = -EPROTO;
731 	} else {
732 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
733 	}
734 
735 out_put_unlock:
736 	mutex_unlock(&call->user_mutex);
737 error_put:
738 	rxrpc_put_call(call, rxrpc_call_put);
739 	_leave(" = %d", ret);
740 	return ret;
741 
742 error_release_sock:
743 	release_sock(&rx->sk);
744 	return ret;
745 }
746 
747 /**
748  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
749  * @sock: The socket the call is on
750  * @call: The call to send data through
751  * @msg: The data to send
752  * @len: The amount of data to send
753  * @notify_end_tx: Notification that the last packet is queued.
754  *
755  * Allow a kernel service to send data on a call.  The call must be in an state
756  * appropriate to sending data.  No control data should be supplied in @msg,
757  * nor should an address be supplied.  MSG_MORE should be flagged if there's
758  * more data to come, otherwise this data will end the transmission phase.
759  */
760 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
761 			   struct msghdr *msg, size_t len,
762 			   rxrpc_notify_end_tx_t notify_end_tx)
763 {
764 	int ret;
765 
766 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
767 
768 	ASSERTCMP(msg->msg_name, ==, NULL);
769 	ASSERTCMP(msg->msg_control, ==, NULL);
770 
771 	mutex_lock(&call->user_mutex);
772 
773 	_debug("CALL %d USR %lx ST %d on CONN %p",
774 	       call->debug_id, call->user_call_ID, call->state, call->conn);
775 
776 	switch (READ_ONCE(call->state)) {
777 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
778 	case RXRPC_CALL_SERVER_ACK_REQUEST:
779 	case RXRPC_CALL_SERVER_SEND_REPLY:
780 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
781 				      notify_end_tx);
782 		break;
783 	case RXRPC_CALL_COMPLETE:
784 		read_lock_bh(&call->state_lock);
785 		ret = call->error;
786 		read_unlock_bh(&call->state_lock);
787 		break;
788 	default:
789 		/* Request phase complete for this client call */
790 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
791 		ret = -EPROTO;
792 		break;
793 	}
794 
795 	mutex_unlock(&call->user_mutex);
796 	_leave(" = %d", ret);
797 	return ret;
798 }
799 EXPORT_SYMBOL(rxrpc_kernel_send_data);
800 
801 /**
802  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
803  * @sock: The socket the call is on
804  * @call: The call to be aborted
805  * @abort_code: The abort code to stick into the ABORT packet
806  * @error: Local error value
807  * @why: 3-char string indicating why.
808  *
809  * Allow a kernel service to abort a call, if it's still in an abortable state
810  * and return true if the call was aborted, false if it was already complete.
811  */
812 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
813 			     u32 abort_code, int error, const char *why)
814 {
815 	bool aborted;
816 
817 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
818 
819 	mutex_lock(&call->user_mutex);
820 
821 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
822 	if (aborted)
823 		rxrpc_send_abort_packet(call);
824 
825 	mutex_unlock(&call->user_mutex);
826 	return aborted;
827 }
828 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
829 
830 /**
831  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
832  * @sock: The socket the call is on
833  * @call: The call to be informed
834  * @tx_total_len: The amount of data to be transmitted for this call
835  *
836  * Allow a kernel service to set the total transmit length on a call.  This
837  * allows buffer-to-packet encrypt-and-copy to be performed.
838  *
839  * This function is primarily for use for setting the reply length since the
840  * request length can be set when beginning the call.
841  */
842 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
843 				s64 tx_total_len)
844 {
845 	WARN_ON(call->tx_total_len != -1);
846 	call->tx_total_len = tx_total_len;
847 }
848 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
849